Assessing performance of conservation-based Best Management Practices: Coarse vs. fine-scale analysis

Background/Questions/Methods
Animal agriculture in the Spring Creek watershed of central Pennsylvania contributes sediment to the stream and ultimately to the Chesapeake Bay. Best Management Practices (BMPs) such as stream bank buffers are intended to intercept sediment moving from heavy-use areas toward the stream. The placement of BMPs on a farm is generally based on untested assumptions about flow paths. Most often, a straight-line distance from the heavy-use area to the stream is assumed to be correct. Our objective was to compare the straight-line path to hydrologic flow paths calculated from fine-, medium- and coarse-grained Digital Elevation Models (DEMs; 1m, 10m, 30m) for 471 mapped heavy-use points within 100m of the stream. The 30m DEMs are the most widely available and require the least processing time. We anticipated that the flow path distance would be longer than the straight-line distance in all cases, that the finest resolution would lead to the most accurate measurement, but that the difference might not be great enough to justify the increased costs. Understanding the changes in path length and direction calculated using more complex methods and higher-resolution source data will enable us to make recommendations on methods to be used in developing conservation management plans.

Results/Conclusions
The medium-(10m DEM) and fine-resolution data (1m DEM) had the smallest differences between the hydrologic flow path and straight-line path: median differences in path length of 20 m for both the 1m and 10m DEMs, and 51m for the 30m DEM. Hydrologic flow paths were significantly longer than straight-line paths for all three scales; BMP placement based on straight-line distances may not be the most effective. Although the overall difference was significantly positive, calculations on the 30m DEMs sometimes produced straight-line paths that were longer than the hydrologic flow paths, apparently due to inaccuracies in the data. Where fine-scale DEMs are available, BMPs might be more effectively situated by considering the corresponding drainage pathways. The very different results produced at the three scales demonstrate that using the finest-grained elevation data may substantially improve placement of BMPs intended to mitigate for heavy animal use areas. The use of 30m DEMs for this purpose should be avoided. Fine-grained data such as 1m-resolution LiDAR-derived DEMs are available for Pennsylvania through PAMAP, and can be incorporated in the planning stages of BMP placement ultimately resulting in reducing agricultural sediment and nutrient loadings into local watersheds and the Chesapeake Bay

The Gore Hybrid Vascular Graft in renovisceral debranching for complex aortic aneurysm repair

Objective This study reports our initial experience with the Gore Hybrid Vascular Graft (GHVG; W. L. Gore & Associates, Flagstaff, Ariz) for staged hybrid open renovisceral debranching and endovascular aneurysm repair in patients affected by thoracoabdominal aortic aneurysms and pararenal abdominal aortic aneurysms (PAAAs). Methods Between December 2012 and December 2013, we analyzed outcomes of 13 patients who underwent open surgical debranching of renovisceral vessels for thoracoabdominal aortic aneurysm and PAAAs. All patients were considered at high risk for conventional surgery. Inclusion criterion was treatment by open surgical debranching of at least one visceral artery (renal artery, superior mesenteric artery [SMA], or celiac trunk [CT]) using the GHVG. In a second step, the aortic stent graft was implanted to exclude the aneurysm. If required, parallel grafts to the remaining visceral arteries were deployed in the same procedure. One patient had a symptomatic descending thoracic aortic aneurysm and another had a ruptured PAAA. Perioperative measured outcomes were immediate technical success rate, mortality, and morbidity. Median follow-up was 24.8 months (range, 0-15; mean, 8.2; standard deviation, 4 months). Results All open surgical debranching of renovisceral vessels were completed as intended. GHVG was used to revascularize 20 visceral vessels in 13 patients with a mean of 1.54 vessels per patient. Six renal arteries (30%; 2 right and 4 left), 9 SMAs (45%), and 5 CTs (25%) were debranched. In nine of 13 (66%) patients, other renovisceral arteries were addressed with chimney/periscope, Viabahn Open Revascularization Technique, and end-to-side anastomosis. Two of 13 patients (15%) died of bowel ischemia. Neither patient had GHVG revascularization to the SMA or CT. Perioperative complications occurred in three patients (23%; 1 renal hematoma, 1 respiratory insufficiency, and 1 small-bowel ischemia related to a SMA GHVG thrombosis). At 24 months, estimated survival was 85%, and estimated primary and secondary patency were 94% and 100%, respectively. Conclusions This limited series extracted from a more consistent hybrid procedure experience showed a mortality rate similar to most recent reports. Technical feasibility and the short-term patency rate of the GHVG for renovisceral debranching during staged hybrid open and endovascular procedures were satisfactory. Use of GHVGs may represent a useful revascularization adjunct to minimize visceral ischemia in these challenging patients

Use of the STAT (Sutureless Telescoping Anastomosis Technique) to facilitate supraaortic revascularization: Mid-term Results

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Electrophysiological Guidance of Epidural Electrode Array Implantation over the Human Lumbosacral Spinal Cord to Enable Motor Function after Chronic Paralysis.

Epidural electrical stimulation (EES) of the spinal cord has been shown to restore function after spinal cord injury (SCI). Characterization of EES-evoked motor responses has provided a basic understanding of spinal sensorimotor network activity related to EES-enabled motor activity of the lower extremities. However, the use of EES-evoked motor responses to guide EES system implantation over the spinal cord and their relation to post-operative EES-enabled function in humans with chronic paralysis attributed to SCI has yet to be described. Herein, we describe the surgical and intraoperative electrophysiological approach used, followed by initial EES-enabled results observed in 2 human subjects with motor complete paralysis who were enrolled in a clinical trial investigating the use of EES to enable motor functions after SCI. The 16-contact electrode array was initially positioned under fluoroscopic guidance. Then, EES-evoked motor responses were recorded from select leg muscles and displayed in real time to determine electrode array proximity to spinal cord regions associated with motor activity of the lower extremities. Acceptable array positioning was determined based on achievement of selective proximal or distal leg muscle activity, as well as bilateral muscle activation. Motor response latencies were not significantly different between intraoperative recordings and post-operative recordings, indicating that array positioning remained stable. Additionally, EES enabled intentional control of step-like activity in both subjects within the first 5 days of testing. These results suggest that the use of EES-evoked motor responses may guide intraoperative positioning of epidural electrodes to target spinal cord circuitry to enable motor functions after SCI

Syntheses, Structures, and Photophysical Properties of Mono- and Dinuclear Sulfur-Rich Gold(I) Complexes

Sulfur-rich 1,2 dithiolene and neutral thione ligands were used for the synthesis of gold complexes, some of them exhibiting aurophilic interactions. Surprisingly, the closest Au···Au contact is observed in an unsupported dinuclear complex, which makes part of a supramolecular network. Photophysical studies, combined with DFT calculations, indicate that the participations of the Au···Au interactions have some relevance to the rich luminescence properties of these compounds

Estimating damages from price-fixing: the value of transaction data

We use a unique private data set of about 340,000 invoice positions from 36 smaller and larger customers of German cement producers to study the value of such transaction data for an estimation of cartel damages. In particular, we investigate, first, how structural break analysis can be used to identify the exact end of the cartel agreement and, second, how an application of before-and-after approaches to estimate the price overcharge can benefit from such rich data sets. We conclude that transaction data allows such a detailed assessment of the cartel and its impact on direct customers that its regular application in private antitrust cases is desired as long as data collection and preparation procedures are not prohibitively expensive

Visible light induced RAFT for asymmetric functionalization of silica mesopores

One key feature for bioinspired transport design through nanoscale pores is nanolocal, asymmetric as well as multifunctional nanopore functionalization. Here, we use a visible-light induced, controlled photo electron/energy transfer-reversible addition–fragmentation chain-transfer (PET-RAFT) polymerization for asymmetric polymer placement into mesoporous silica thin films including asymmetric polymer sequence design

Istmikunärvi iatrogeenne vigastus

Eesti Arst 2015; 94(9):559–56